1. Field of the Invention
The present invention relates to evaporative coolers used in semi-dry climates for cooling of buildings such as residential homes. Such evaporative coolers are often referred to as swamp coolers. In particular, the invention relates to alarm devices for giving a warning alarm that the water level in the reservoir of an evaporative cooler has become sufficiently deep so that water is overflowing from the reservoir.
2. State of the Art
Evaporative coolers are used widely in semi-dry climates for cooling air which is being introduced through the cooler to a building. Water is distributed over pads in the housing of the evaporative cooler, and as relatively dry air passes through the wet pads water is evaporated. The evaporation of the water takes heat from the air and thus reduces the temperature of the air. In semi-dry climates, evaporative coolers are very efficient, low cost means for cooling the air within a building.
All evaporative coolers must have a reservoir of water that is used to recirculate over the pads through which the air passes. As the water is evaporated, the level of the water in the reservoir drops, and a float valve turns on to introduce make-up water to the reservoir through a water supply conduit.
The float valves are prone to malfunction, usually failing to close when the reservoir is properly filled thus allowing excess water to enter into the reservoir. Virtually all evaporative coolers are provided with an overflow tube that allows excess water to flow out of the reservoir. The overflow water usually flows on to the roof of the building on which the evaporative cooler is installed. The flow of water over the roof of the building causes ugly water marks on the roof and can eventually cause sufficient damage that the roof must be repaired.
Quite often, the overflow tube is insufficient in size to carry off all the excess water being introduced into the water reservoir by the malfunctioning float valve, such as when the overflow tube becomes partially blocked with debris. When this occurs, there is a high probability that the water level will rise sufficiently in the reservoir to leak into the interior of the building. Such water leaking into the interior of the building can cause major damage that is very costly to repair.
An extensive search of prior art patents relating to evaporative coolers indicates that the problems resulting from malfunctioning float valves have not been adequately addressed. There was no prior art found that relating to means for monitoring the level of water in the reservoir or an evaporative cooler or of giving a warning that excess water is being discharged from the evaporative cooler through the overflow tube. Without any warning of such a condition, the inhabitants of the building may delay for some time to determine that the evaporative cooler is malfunctioning. Overflow water in the mean time can be causing serious damage to the roof of the building or to the interior of the building when the overflow water is leaking to the interior.